Description: Optimize file descriptor closing
 Closing all the fds is a severe performance issue in containers when
 ulimit is high. We fixed that in APT a long time ago, time to apply
 the same fix here.
Author: Julian Andres Klode <juliank@ubuntu.com>

--- a/faked.c
+++ b/faked.c
@@ -107,6 +107,7 @@
 #ifdef HAVE_SYS_XATTR_H
 #include <sys/xattr.h>
 #endif
+#include <dirent.h>
 #include <fcntl.h>
 #include <ctype.h>
 #include <stdio.h>
@@ -1502,16 +1503,32 @@ int main(int argc, char **argv){
     /* literally copied from the linux klogd code, go to background */
     if ((pid=fork()) == 0){
       int fl;
-      int num_fds = getdtablesize();
+      DIR *dir;
 
-      fflush(stdout);
+      dir = opendir("/proc/self/fd");
+      if (dir != NULL) {
+	    struct dirent *ent;
+		int dfd = dirfd(dir);
+	    while (ent = readdir(dir)) {
+		fl = atoi(ent->d_name);
+		if (fl >= 0 && fl != dfd)
+#ifdef FAKEROOT_FAKENET
+		    if (fl != sd)
+#endif /* FAKEROOT_FAKENET */
+			close(fl);
+	    }
+	    closedir(dir);
+      }
+      else {
+	  int num_fds = getdtablesize();
 
-      /* This is the child closing its file descriptors. */
-      for (fl= 0; fl <= num_fds; ++fl)
+	  /* This is the child closing its file descriptors. */
+	  for (fl= 0; fl <= num_fds; ++fl)
 #ifdef FAKEROOT_FAKENET
-	if (fl != sd)
+	    if (fl != sd)
 #endif /* FAKEROOT_FAKENET */
-	  close(fl);
+	      close(fl);
+      }
       setsid();
     } else {
       printf("%li:%i\n",(long)FAKE_KEY,pid);